是否可以将另一个较小的图像添加到UIImage / UIImageView?如果是这样,怎么样?如果没有,那我怎么画一个小的三角形?
由于
答案 0 :(得分:38)
您可以为UIImageView
添加一个子视图,其中包含另一个带有小填充三角形的图像。或者你可以在第一张图片内画画:
CGFloat width, height;
UIImage *inputImage; // input image to be composited over new image as example
// create a new bitmap image context at the device resolution (retina/non-retina)
UIGraphicsBeginImageContextWithOptions(CGSizeMake(width, height), YES, 0.0);
// get context
CGContextRef context = UIGraphicsGetCurrentContext();
// push context to make it current
// (need to do this manually because we are not drawing in a UIView)
UIGraphicsPushContext(context);
// drawing code comes here- look at CGContext reference
// for available operations
// this example draws the inputImage into the context
[inputImage drawInRect:CGRectMake(0, 0, width, height)];
// pop context
UIGraphicsPopContext();
// get a UIImage from the image context- enjoy!!!
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
// clean up drawing environment
UIGraphicsEndImageContext();
此代码(source here)将创建一个新UIImage
,您可以使用它来初始化UIImageView
。
答案 1 :(得分:22)
你可以尝试这个,对我来说很完美,它是UIImage类别:
- (UIImage *)drawImage:(UIImage *)inputImage inRect:(CGRect)frame {
UIGraphicsBeginImageContextWithOptions(self.size, NO, 0.0);
[self drawInRect:CGRectMake(0.0, 0.0, self.size.width, self.size.height)];
[inputImage drawInRect:frame];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
或斯威夫特:
extension UIImage {
func image(byDrawingImage image: UIImage, inRect rect: CGRect) -> UIImage! {
UIGraphicsBeginImageContext(size)
draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
image.draw(in: rect)
let result = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return result
}
}